Blasting cartridge



I A //J H I IN VEN TOR. 27mm? 120%? B Y a I? A! T A TTORNEY Patented June 15, 1937 UNITED STATES PATENT OFFIQE ems-mm can'mmcn Application December I, 1934, Serial No. 756,512

18 Claims.

This invention relates to blasting cartridges, and more particularly to improvements in a blasting cartridge of the type known as an "air shell" wherein a high pressure gas is employed as a blasting medium.

An object of this invention is to provide an improved blasting cartridge of the type known as an air shell designed for use in the air shooting" of coal or similar materials. Another object is to provide an improved cartridge having its connection with a high pressure gas source and its discharge means for the blasting charge arranged at the same end of the pressure container. A further object is to provide in a blasting cartridge i5 01 the above character an improved combined terminal cap and discharge head formed in a single element and arranged at the outer end of the pressure container. Yet another object is to provide an improved cartridge having pressure discharge means controlled by a differential valve mechanism, the discharge control valve arranged at the outer end of the pressure container and the control chamber containing a valve control plunger arranged at the inner end of the pressure container. These and other objects will, however,

subsequently more fully appear.

In the accompanying drawing there is showh for purposes of illustration one form which the invention may assume in practice. In this drawing,---

The figure is a view in longitudinal section of the illustrative embodiment of the improved blasting cartridge.

In this illustrative construction there is shown 5 a blasting cartridge of, the type known as an air shell wherein a high pressure gas such as air compressed under high pressure, is employed as a blasting medium and this cartridge comprises a pressure container l of elongated cylindrical form having a pressure chamber 2. Threadedly secured at 3 within the .inner end of the container is a control cap 5, while threaded within the outer end of the container at 5 is a combined terminal cap and discharge head 6. This element t has an axial discharge orifice l terminating in radial discharge ports 5. A conical control valve 9 seats on the wall surrounding the inner end of the discharge orifice l to close the outer end of the pressure chamber 2, and this valve has an axial guide extension til which cooperates with a bore formed in the element 5 to center and guide the valve 9 with respect to its seat. Formed in the control can t is an axial control chamber ll containing a plunger l2 con nected by a valve rod is to the valve 9, this valve rod extending axially within the pressure chamber 2 and threadedly secured to the valve 9 at M. body is a cup leather l5 held in position by a keeper Hi threaded on the valve rod, and this cup leather serves to prevent leakage of high pressure gas from the outer end of the control chamber past the plunger to the inner end of the control chamber at the inner side of the plunger. Held in position within the inner end of the container by the cap 4 is a metallic plate ll through which the valve rod extends and which carries a hat leather l8 which seals the valve rod and functions as a check valve to prevent leakage from the control chamber past the valve rod to the pressure chamber 2 while permitting flow of high pressure gas from the pressure chamber past the valve rod to the outer end of the control cham her at the outer side of. the plunger. The valve rod I3 is preferably made in two parts secured together by a connecting member it hav ing arranged therein a valve chamber for receiving a ball check valve 20. The valve rod is axially bored at 2! and communicates at its inner end through a passage 22 in the plunger 2 with the control chamber II at the inner side of the plunger, and through a passage 23 controlled by the check valve 20 with the pressure chamber 2. High pressure gas from any suitable source is conducted, under remote control, through tubing 26 connected by a nipple 25 to a plug 28 secured within the element 8. The plug 26 is provided with an axial bore 21 which conducts fluid to a bore 28 formed in the valve guide extension it: and valve 9 and communicating with the bore ill of the valve rod. The element 6 contains a packing at 29 to prevent leakage of fluid past the guide extension Hi to the discharge orifice ll.

To perform the blasting operation, the cartrldge is placed in a drill hole in the material to be broken and is suitably held therein as by tamping and the tubing 24 extended from the cartridge to a suitable source of high pressure gas. When the cartridge is so positioned, high pressure gas, controlled from aremote point, is admitted through the tubing 26, through the bore 28 in the valve guide extension and valve. through the valve rod bore 2|, and past the check valve 20, through the passagett to the pressure chainber 2. At the same time fluid flows throughthe valve rod bore, through passage 22 to the corn trol chamber II at the inner side of the plunger it, the pressure acting on the inner pressure area of this plunger to hold the valve 9 firmly against its seat. When a predetermined blasting Secured to the outer face-of the plunger pressure is attained within the pressure chamber 2 the supply or high pressure gas to the tubing 24 is cut 011 and the pressure in this tubing suitably vented to atmosphere or otherwise reduced. The pressure in the control chamber Ii at the outer side of the plunger l2, acting on the outer pressure area of the plunger, moves the latter inwardly when the pressure at the inner side of the plunger has been reduced, thereby moving the control valve 9 into its open position, and as a result the'blasting charge is suddenly discharged i'rom the chamber 2 through the discharge orifice I and radial discharge ports 8 to act on the material to be broken. Obviously the valve 20 may be suitably loaded to insure. pressure within the extreme inner end of chamber I I closing valve 9 before pressure flows into chamber 2; though of course the operator will preferably cause the valve 9 to be closed before beginning to admit pressure through the line 24. These and other uses and advantages of the improved blasting cartridge will be clearly apparent to those skilled in the art.

While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration, and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a blasting cartridge, a container having an orifice at its outer end through which fluid may be discharged, means at the outer end of the container for charging it with a highly compressed fluid, and a fluid pressure controlled valve at the outer end of said container for controlling said discharge orifice and moving inwardly to open the same.

2. In a blasting cartridge, a container adapted to be charged with a highly compressed fluid and having an orifice at its outer end through which such fluid may be discharged, a fluid pressure controlled valve at the outer end of said container for controlling said discharge ori'flce, control means arranged at the inner end of the container for controlling said valve, and means for both conducting compressed air to the container and operatively connecting the valve and control means.

3. In a blasting cartridge, a container having a discharge orifice at its outer end through which fluid may be discharged, means at the outer end of the container for charging it with a highly compressed fluid, and a fluid pressure controlled valve for governing said orifice and positioned at the discharge end of said container adjacent said orifice and moving inwardly to open the same.

4. In a blasting cartridge, a container adapted to be charged with a highly compressed fluid and having at its outer end a combined terminal cap and discharge head through which the container is charged and said fluid may be discharged, a fluid pressure controlled valve for governing said orifice and positioned within said container adjacent said orifice, and control means for said valve arranged at the inner end of said container.

5. In a blasting cartridge, 9. container having at its outer end an orifice through which fluid may be discharged, means at the outer end of the container for charging it with a highly compressed fluid, and a fluid pressure controlled valve operative in one position to seal said orifice and positioned in the container between said orifice and the inner end of said container.

6. In a blasting cartridge, a container adapted to be charged with a highly compressed fluid having an orifice at its outer end through which such fluid may be discharged, and a fluid pressure controlled valve for governing said orifice, said valve being positioned at the discharge end of said container adjacent said orifice, control means for said valve arranged at the inner end of said container, and means for conducting fluid pressure from the outer end of said container to the inner end thereof to actuate and control said valve control means and to charge said container.

7. In a blasting cartridge, a container having a pressure receiving chamber, a combined discharge head and terminal charging cap secured to the outer end of said container, a control cap secured to the inner end of said container, said discharge head having a discharge orifice, a valve for controlling the discharge of pressure from said chamber through said orifice, and a control plunger reciprocable in a bore in the control cap and connected to said valve.

8. In a blasting cartridge, a container having a pressure receiving chamber, a combined discharge head and terminal cap secured to the outer end of said container, a control cap secured to the inner end of said container, said discharge head having a discharge orifice, a valve for controlling the discharge of pressure from said chamber through said orifice, a control plunger reciprocable in a bore in the control cap and connected to said valve, and means at the outer end of said container for supplying high pressure gas to said pressure chamber and said control chamber.

9. In a blasting cartridge, a container having an orifice at its outer end through which fluid may be discharged, means at the outer end of said container for charging it with a highly compressed fiuid, a fluid pressure controlled valve at the outer end of said container for controlling said discharge orifice, and control means arranged at the inner end of the container and mechanically connected with said valve for controlling the latter.

10. In a blasting cartridge, a container having an orifice at its outer end through which fluid may be discharged, means at the outer end of the container for charging it with a highly compressed fiuid. a fluid pressure controlled valve at the outer end of said container for controlling said discharge orifice, and control meansarranged at the inner end of said container beyond the inner end of said chamber for controlling said valve.

11. In a blasting cartridge, a container having a discharge orifice at its outer end through which fluid may be discharged, means at the outer end of the container for charging it with a highly compressed fluid, a fluid pressure controlled valve for governing said orifice and positioned at the discharge end of said container adjacent said orifice, and control means for said valve including a pressure fluid actuated member at the inner end of said container.

12. In a blasting cartridge, a container providing a chamber adapted to be charged with a highly compressed fiuid and having a discharge orifice and a valve for controlling said orifice, controlling means. for said valve, and means for supplying fluid to said chamber and valve conviding a chamber adapted to be charged with a which ismovable into said chamber to open, cony 2,088,979 a trolling means including a passage formed in and extending through said valve.

13. In a blasting cartridge, a container prohighly compressed fluid and having a discharge orifice and a valve for controlling said orifice, and having seat and back portions, controlling means for said valve, and means for supplying fluid to said chamber including a passage formed in said valve for conducting fluid through the latter in the direction from seat to back thereof.

14. In a. blasting cartridge. a container providing a chamber adapted to be charged with a highly compressed fluid and having a discharge orifice and a; valve for controlling said orifice ceiving a charge 0! blasting pressure, discharge means at the outer end of said container, pressure controlled control means at the inner end of said. container operative, while the container pressure remains constant, to efiect opening movement of said discharge means, for governing said discharge means, and means at the outer end of said container for charging the same.

17. In a blasting cartridge, a container for receiving a charge of blasting pressure, discharge means at the outer end of said container, pressure controlled control means at the inner end of said container for governing said discharge means, and means at .the outer end of said container for charging the same and delivering pressure to said control means.

18; In a blastingcartridge, a containeraapartial/W: ,7

tion adjacent the inner end of the container for dividing it into a blasting charge receiving chamber outwardly of the partition and a control chamber inwardly of the partition, discharge means for the blasting chamber at the outer end of said container, and pressure controlled control means positioned entirely within the control chamber operative when the pressure in the charge receiving chamber is superatmospheric and while said pressure remains uniform to effect opening of said discharge means.

- FRANK H. ARMSTRONG. 

